1. Field of the Invention
The present invention relates to an electronic equipment, and more particularly to an electronic equipment incorporating a printed circuit board with electronic parts mounted thereon.
2. Description of the Related Art
In conventional electronic equipments, heat sinks are fixed to individual electronic parts in order to radiate heat generated by the electronic parts through the heat sinks. The radiated heat is forcibly cooled by a fan. In the case of an electronic equipment such as a power converter mounted in an automobile, a printed circuit board with various electronic parts mounted thereon is used by being installed in a housing, so as to be protected from foreign objects such as dust and radiation noise from other electronic equipment. Generally, a box-shaped case divided into two parts of upper and lower parts is used as the housing.
FIG. 8 shows the interior of a conventional electronic equipment before the electronic equipment is built into a housing. Electronic parts 31 have heat sinks 32 attached thereto, and are mounted on a printed circuit board 33. A fan 34 is disposed in the center of an end portion of the printed circuit board 33. The printed circuit board 33 is built into the housing, which is not shown in FIG. 8. Accordingly, air heated by the heat sinks 32 is exhausted to outside the housing by the fan 34. However, there has been a problem in that, in conjunction with a tendency toward a higher output of electric power, the amounts of heat generated by the electronic parts 31 increase, resulting in insufficiency of radiating areas of the heat sinks 32.
In JP-A-2002-353677, there is proposed a heat radiating structure in which electronic parts are effectively cooled by controlling the flow of air due to the heat of the interior of the equipment (c.f. paragraphs [0009]–[0012], FIGS. 1 and 2). In the radiating structure disclosed in JP-A-2002-353677, electronic parts, a tubular heat radiating member, and a fan are mounted on a printed circuit board, and are built in the interior of a box-shaped housing. An electronic part is secured to a heat radiating member, and is mounted on the printed circuit board. The fan sends air in a direction toward the interior of the heat radiating member to cool the heat radiating member. Accordingly, the electronic part does not assume a high temperature, and its characteristics do not deteriorate.